Apparatus for shifting filter plates in a filter press

ABSTRACT

An apparatus for effecting the separation of filter plates within a filter press is disclosed. The apparatus includes a guide track having mounted thereon a slidably reciprocal carriage. The carriage includes at least one pivoted pawl having an abutment space defined thereon for contacting a filter plate to be transported. The pawl is held in a raised orientation by a resilient spring means. The carriage is driven along the guide track by means of a pressure displaced piston mechanically associated therewith. The piston is housed within a tubular member. Positioned within the tubular member are two pressure chambers, one on each end of the piston. Pressurized fluid is controlledly introduced into one or the other of those chambers to effect a displacement of the piston. The pressure cylinder is of the type generally designated a rodless cylinder.

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 312,910, filed Feb. 21, 1989, now U.S. Pat. No. 5,006,241 whichis a continuation of U.S. patent application Ser. No. 936,091, filedNov. 28, 1986 now U.S. Pat. No. 4,806,239.

BACKGROUND OF THE INVENTION

1. Field

This invention relates to filter presses, specifically presses having aplurality of filter plates adapted for removing or separating solidsfrom liquids. More particularly, this invention is directed to apparatusfor separating the filter plates within such a filter press.

2. Statement of the Art

The type of apparatus, known generally as a filter press, is well knownin the art. These apparatus are used in various industries to separatesolids from liquids. Filter presses may be used to separate solids fromsuspensions, slurries, and similar aqueous feed streams. Filter pressesfind application in a variety of industries, e.g. sewage treatment andmining operations.

A filter press generally includes a plurality of separable plates. Theseplates are slidably held on a frame structure between a fixed supportand an opposing moveable support. This moveable support is actuatedtypically by a hydraulic ram.

The plates are typically arranged in parallel about a horizontal axis.Each plate includes a depression on its side surface Positioned overthat depression is a filter cloth or fabric Upon the plates beingpositioned adjacent one another, the opposing depressions in adjacentplates form a cavity wherein the filter cloth is suspended. In order toeffect filtering, the plates are compressed one against another by ahorizontally mounted hydraulic ram. The compression of the plates, oneagainst another, serves to form a sealed abutment of each plate againstits neighboring plates. Thereafter, the fluid or solution, to beprocessed, may be injected into the plates and through the variouscavities defined by the adjacent filter plates. Since the feed stream isfed under pressure into the enclosed cavities, the pressure of the feedstream forces the liquid through the filter cloths. The solids withinthe stream are embedded on the filter cloths as the liquid passesthrough the cloths.

When the filtering operation is complete, the hydraulic ram isretracted.

As the filtering plates filter the aqueous feed stream, an increasingquantity of solid material is built up upon the surface of the filtercloths. After reaching a certain quantity, these solid deposits or cakespreclude operation or further use of the filter. In order to continueuse of the filter press, the filter plates must be separated one fromanother and the cakes or solid deposits removed from the filter cloths.

The means and method of separating the filter plates one from another tofacilitate the cleaning of the filter cloths is a problem which hasconfronted the industry for many years. The most rudimentary approach toseparating these cloths involves the manual efforts of two or more menusing crowbars or other type of wedges to separate one plate from itsneighboring plate. Since the plates are forced against one another by ahydraulic ram and further, since various deposits within the filterpress itself serve to coalesce and thereby bond one plate to another,the amount of force which must be applied to a filter plate to effectits separation from a neighboring plate may be considerable.Furthermore, the use of human labor in this type of environment involvesa considerable amount of safety risk and cost.

As a result, various attempts have been made in the past to deviseautomated separation systems for use in separating the plates in thefilter press after filtration has been effected. Representative of someof these attempts are those which are described in Broad U.S. Pat. No.4,102,788, Krivec U.S. Pat. No. 4,359,385, Busse, et al. U.S. Pat. No.3,915,863, Fismer U.S. Pat. No. 3,232,435, Schotten U.S. Pat. No.4,272,376, Sakuma U.S. Pat. No. 4,132,647 and U.S. Pat. No. Fismer4,105,560.

SUMMARY OF THE INVENTION

The instant invention is directed principally for use in a filter presshaving an elongated frame and a plurality of filter plates mounted to beslidable along that frame, i.e. along the longitudinal axis of theframe. The plates are positioned between a stationary support and amoveable plate which is displaced by a hydraulic ram or other drivingmeans.

The automatic filter plate shifter of the invention includes a guidetrack which is positioned proximate the filter plates. The guide trackis oriented to be substantially parallel to the longitudinal path of thefilter plates within the press. Slidably mounted on that guide track isa carriage which is adapted to reciprocate on the track, thereby movingalong that track in both a forward and backward direction, i.e. alongsubstantially its full length. The carriage includes at least one firstpawl, which is positionable on that carriage in two orientations orconditions. In its first orientation or condition, the pawl is raisedabove the surface of the carriage. In its second orientation, the pawlis positioned substantially lower than its first orientation. The pawlmay, in some instances, actually be positioned below the uppermostsurface of the carriage itself. The pawl is pivotally mounted to thecarriage so as to be reciprocal between the first and secondorientation. A resilient support means which is mounted on the carriageand associated with the first pawl continuously urges that pawl into itsfirst, i.e. raised, orientation.

The first pawl includes an abutment surface which is configured upon thefirst pawl reaching its raised orientation, to firmly contact a filterplate. As the carriage is displaced in a first direction, the abutmentsurface transfers the momentum of the carriage against the filter platethereby pushing against the filter plate and effecting a correspondingdisplacement of that plate. In preferred constructions, the first pawlalso includes a sliding surface. The sliding surface is typically aplanar surface positioned in an angulated orientation. This slidingsurface is adapted to contact slidingly the filter plates as thecarriage is displaced in a second direction. As the sliding surfacecontacts a filter plate, the contact shifts the first pawl from itsraised condition to its lowered condition. In this lowered condition theabutment surface is substantially held out of contact with the filterplate The sliding surface permits the first pawl to be shifted to itslowered condition and thereafter displaced in a second direction beyonda filter plate or plate(s) mounted adjacent to the pawl's track. Oncepast the plates, the first pawl is returned to its raised orientation.The direction of the first pawl's travel may then be reversed, i.e. tothe first direction bringing the abutment surface into contact with thefilter plate. A further displacement of the carriage/pawl assemblyeffects a displacement of the filter plate in the direction of movementof the carriage pawl assembly, i.e. the first direction.

In some embodiments, a second pawl, as distinguished from the heretoforedescribed first pawl, is pivotally mounted on the carriage and ispositioned substantially opposite the mounting of the first pawl.Similar to the first pawl, the second pawl is mounted to be positionablein two orientations or conditions. In its first orientation the secondpawl is positioned in a raised orientation to extend beyond theuppermost surface of the carriage. In its second, or loweredorientation, the pawl is positioned below the height or altitude of itsraised orientation and may in some instances be actually positionedbelow the uppermost surface of the carriage. The second pawl alsoincludes an abutment face and an angulated sliding surface. The secondpawl's abutment face may be positioned opposite the abutment face of thefirst pawl. The angulated sliding surface of the second pawl may bepositioned substantially at angle of 90° from that of the first pawl.

In preferred constructions, the pivot mountings of both the first andthe second pawl permit the rotation of each pawl about an axis which issubstantially horizontal. Further, that rotational axis may also beoriented to be substantially perpendicular to the longitudinal axis ofthe filter press frame. In some constructions, the pawls rotate in avertical plane which is parallel to the longitudinal axis of thecarriage and the longitudinal axis of the frame, as well as parallel tothe direction of travel of the carriage along the guide track. Similarto the first pawl, the second pawl also includes a resilient supportmeans associated therewith which is adapted to urge the second pawlcontinuously into its first or raised orientation.

A restraining means may be associated with the carriage and is adaptedfor interaction with the first pawl. The restraining means is adapted toshift the first pawl into its lower orientation and hold it in thatparticular orientation. While the restraining means retains the firstpawl in its lower orientation, the second pawl continues to be urgedupward, by its resilient support means, into its raised orientation. Theaction of the restraining means provides a means whereby the carriagemay be directed to pass along the guide track in the first directionwhile avoiding any substantial displacement-limiting contact between thepawls and the filter plates. This passage is important since therelative positioning of the carriage vis-a-vis the filter plates must betransposed when the opening of the entire collection of filter plateshas been accomplished. Stated otherwise, the carriage operates to shifteach plate from a closed configuration on one fixed end of the pressframe to an open configuration on the moveable opposing end of the sameframe. When the last plate has been shifted to the moveable opposingend, the carriage is positioned between the open plates and the fixedend. To repeat the filtering operation, the plates must be displaced tothe fixed end and reassembled in their closed configuration. Inaccomplishing this displacement, the plates typically must pass by thecarriage or alternately the carriage must pass by the plates. Therestraining means facilitates this passage by arranging the pawls toslide past the plates without effecting any solid abutment-type contactof the pawls against the plates.

In a preferred construction this restraining means includes a pair ofparallelly oriented shaft-like members which are slidably mounted withinchannels defined by the structure of the carriage. The shaft members areslidable along the longitudinal axis of the carriage. The carriagelongitudinal axis is parallel to the longitudinal axis of the frame.Positioned between each of the two parallel and spacedly mounted shaftmembers are two cross-members which extend from one shaft member to theother shaft member. These cross-members are generally aligned to beperpendicular to the longitudinal axis of the carriage. The assembly ofthe shaft members with their attendant cross-members is made slidablelongitudinally within the carriage. As the shaft/cross-member assemblyslides, one of the cross-members is brought into abutment against theupper surface of the first pawl, and thereby serves to restrain ordepress that pawl into its lowered orientation.

The carriage is mechanically associated with a drive means. Preferablythis drive means is a piston, which piston is reciprocally mountedwithin a tubular member. The tubular member is associated with the frameof the filter press. The tubular member includes a sidewall whichextends longitudinally along the length of the filter press frame. Thetubular member defines two oppositely-positioned pressure chamberswithin the hollow interior of that tubular member. The piston ispositioned between those pressure chambers As the pressure is variedwithin those two pressure chambers the piston is displaced within thetubular member, the displacement or reciprocation of the piston effectsa corresponding displacement of the carriage along the guide track.

In one embodiment, the tubular member defines a slot-like aperture whichextends along its length. A bracket mounting of the piston to thecarriage member is slidably fitted into the slot. The tubular member isfitted with a means of successively sealing the slot during the movementof the piston within the tubular member. This sealing permits thepressurization of the two opposing pressure chambers. Thispressurization effects the displacement of the piston within the tubularmember.

In another construction, the opposing ends of the piston are eachfixedly mounted to an end of a belt-like member. This member extendsfrom its end mounting through the length of a respective pressurechamber and exits that chamber and the tubular member through anotherwise sealed port. The belt in association with the piston forms anendless belt member. The carriage is mounted to this belt-like member ona region thereof external to the tubular housing. As the piston isdisplaced, the belt is correspondingly displaced. Resultingly, thecarriage is likewise displaced.

A further construction involves the use of a magnetic association of thecarriage with the piston. In this embodiment, the tubular housing isconstructed of non-magnetic material, the piston is fabricated ofmagnetic material. A collar of ferrous material is slidably mounted onthe exterior of the tubular housing and made reciprocable along thesurface of that housing. The carriage is fixedly mounted to that collar.As the piston reciprocates within the housing, the momentum of itsmovement is translated to the collar/carriage assembly by means of themagnetic relationship between the collar and the piston.

The introduction of pressurized fluid into either of the pressurechambers, defined within the tubular member, is manipulated by a controlsystem. This control system operates to channel pressurized fluid toeffect a displacement of the carriage in a second direction until a pawlon the carriage is brought into an abutting orientation against thesurface of a filter plate.

In those constructions utilizing a two-pawl arrangement, once theabutment surface of the second pawl is brought into an abutment againstthe filter plate the abutment results in an introduction of the filterplate into the space between the two opposing pawls. The filter plate isabutted against the abutment surface of the second pawl on one side andagainst the abutment surface of the first pawl on an opposing side.Since the filter plate is adjacent a neighboring series of plates, whichthemselves are abutted against a firmly positioned support, thecontinued channeling of pressurized fluid to the pressure chamber servesto augment the pressure within that chamber, without any correspondingdisplacement of the filter plate. As the pressure within the pressurechamber builds and surpasses a preselected value, the control systemintroduces pressurized fluid into the second or opposing pressurechamber within the tubular member. The pressurized fluid in the formeror first pressure chamber is vented. The introduction of pressurizedfluid into the second pressure chamber effects a displacement of thecarriage in a first direction which is opposite to that effected by thepressurization of the first pressure chamber.

The arrangement of the pawls effects a releasable union of the pawlswith the filter plate upon the abutment of those pawls with the filterplate.

The carriage, through means of the piston, is driven by a sufficientforce to displace the filter plate along a first direction opposite tothat direction obtained by pressurized fluid being channeled into thefirst pressure chamber.

The filter plate is transported to the movable end of the frame. Uponthe plate impacting against an end plate mounted thereon or againstfilter plates abutted against that plate, the filter plate is precludedfrom further displacement in the first direction. Further, the secondpawl upon contacting the cylinder plate or a previously transportedfilter plate, abutting against the cylinder plate, is shifted to itssecond or lowered orientation. In this lowered orientation, the abutmentsurface of the second pawl does not abut against the filter plate.

Due to the filter plates being unable to be further displaced, the fluidpressure in the second cylinder increases until reaching a preselectedlevel. On reaching that pressure level, the second chamber is ventedwhile pressurized fluid is introduced into the first chamber effecting adisplacement of the carriage in the second direction.

The above operation is repeated successively for each filter plate untilthe entire plurality of filter plates is transferred from their loadedor compressed condition to their open configuration on the opposing endof the filter press frame.

The filter press is fitted with two stops which are positioned proximatethe guide track. A first stop is fitted proximate the fixed head plate.A second stop is fitted proximate the location of the moveable supportor follower, when that support is in its withdrawn orientation orconfiguration, i.e., when the hydraulic ram has been withdrawn to permitthe opening of the compressed filter plates.

As the carriage proceeds along the guide track in a second directionafter having transferred all of the filter plates from their closedorientation to their open orientation, the carriage impacts against thefirst stop positioned proximate the fixed head plate. As the carriageabuts against the first stop, the restraining means is actuated. Inpreferred embodiments, the two shaft-like members which extend from thecarriage are driven slidably and longitudinally along the carriage. Thedisplacement of the shaft-like members effects a correspondingdisplacement of the cross-members mounted thereon. One of thecross-members is thereby brought into abutment against the first pawlmember. As the shaft members are driven further along the structure ofthe carriage, the cross-member is driven over the sliding surface of thefirst pawl, thereby depressing that first pawl into its loweredorientation. Once the carriage is unable to proceed further along theguide track in the second direction, as a result of the first stop, thepressure within the tubular member reaches the critical value.Thereafter pressurized fluid is introduced into the opposing pressurechamber or second chamber, effecting a displacement of the carriagemember in the first, i.e., opposite direction to a position proximatethe second stop. Due to the lowered orientation of the first pawl, thecarriage passes unimpeded past the filter plates to a starting positionproximate the moveable follower. The second stop may be fitted with adeactivation button. Upon the carriage being brought into abutmentagainst that second stop, the pressure sensitive disengagement buttondisengages the entire filter press shifting apparatus system.

Prior to a disengagement being effected, the shaft members of therestraining means, which have been previously driven longitudinally andslidably along the length of the carriage by their impact against thefirst stop, impact against the second stop. This impact effects adisplacement of the cross-members to a position wherein the first pawlis released from its lowered position.

The guide tracks of the invention may be positioned adjacent to thefilter plates, i.e., along the sides of the filter plates, to extendsubstantially parallel along the longitudinal axis of the filter press.The tracks may be positioned above the stacked array of filter plateswhile at the same time extending substantially parallel to thelongitudinal axis of the filter press. In preferred constructions aguide track, together with its associated carriage and drive means, ispositioned on each side of the filter plate so as to form a jointtransport means to convey the plates from one location to the other.

In those embodiments which utilize pressurized air in the drive means,the pressurized air may also be utilized to effect a pressurized ormechanical discharge of the filter cakes from the filter clothssuspended between each pair of adjoining filter plates. In a preferredconstruction, the first pawl may be fitted with a conduit therein with aconnected nozzle fitted on the first pawl's abutment surface. Theconduit and nozzle are adapted to receive a supply of pressurized airfrom an external source and direct that flow into the structure of afilter plate being transferred.

In this construction, the filter plate is also fitted with a conduitwhich connects to a port adapted to receive the nozzle of the firstpawl. The conduit is adapted to channel the flow of air to a locationbetween the surface of the filter plate and the interior or back surfaceof the filter cloth suspended over that filter plate. Pressurized airmay be directed from an external source through the first pawl and intothe very structure of the filter plate while it is being transferredfrom one location to another. The pressurized air directed between thefilter plate's exterior surface and the back surface of the filter clotheffects a balloon-like configuration in which the filter cloth isspatially removed from the surface of the filter plate and bowedconvexly outward. This bowing action serves to disrupt the cakeformations on the exterior surface of the filter cloth, thereby aidingand contributing to the discharge of those filter cakes from the surfaceof the filter cloth.

In those constructions of the filter press wherein a pair of rodlesscylinders are used, the cylinders are positioned parallel and spacedlyapart from one another on opposing sides of the frame. Each of thepistons of the two rodless cylinders are connected to their respectivecarriages. In constructions utilizing a single rodless cylinder, auniform or constant velocity displacement of the carriage along thelength of the rodless cylinders is not of particular importance. Shouldthe progress of the carriage be temporarily impeded by the buildup ofsludge or waste on the track, the pressure within the cylinder increasesuntil it reaches a level sufficient to apply a force to the carriageadequate to overcome the resistance created by the sludge or waste. Incontrast, in filter press constructions which utilize a pair of rodlesscylinders, it became important that both of the carriages proceed alongtheir respective rodless cylinders at a uniform rate or velocity. If theuniform velocity is not maintained, one of the carriages tends toadvance ahead of the other, causing the filter plate to be rotated abouta vertical axis. This rotation may cause the plate to be biased againstthe frame sufficiently that its forward progress is arrested. Further,the plate's rotation may actually cause the plate to remove itself fromthe frame. The present invention provides a means of maintaining thevelocities of the two carriages uniform. The filter plate is therebydisplaced by those carriages longitudinally along the frame avoiding anyangular rotation of the plate about a vertical axis.

The two carriages are fitted with a synchronizing means which is mountedto each carriage and extends therebetween. The synchronizing means holdsthe two carriages in a fixed spatial relationship to one another as thecarriages are displaced along the press frame. Should one carriageencounter a hindrance to its displacement, and be slowed or stoppedthereby, the synchronizing means functions to slow or stop the secondcarriage such that it does not advance ahead of the first carriage alongthe press frame. Not only does the synchronizing means control theprogress of the two carriages along the frame, it may also operate as ameans of transferring force from one carriage to the other. Hence, thenon-obstructed carriage may actually apply a force to the impededcarriage to assist in dislodging that impeded carriage.

The invention may also include a stabilizing means adapted to precludean angular or rocking of a filter plate being transported about alongitudinal axis. In those filter press constructions wherein theconnection means engages the filter plates along their upstanding sides,as the connection means applies a force to the plate directedlongitudinally along the length of the filter plate frame, many of theplates tend to rotate or rock about a laterally extending longitudinalaxis. Observably, this rotation impedes the displacement of the platealong the frame as the rocking tends to impede a constant engagement ofthe plate against the connection means. The stabilizing means of theinvention may include a stabilizing means mounted either on the pressframe or on the connection means. The stabilizing means includes asupport frame, and an engagement means adapted to engage and form areleasable union with the filter plate at a location on the plate whichis not collinear with the points of engagement of the two connectionmeans. Hence, the plate is supported by a three-point engagement whereinat most only two of the points are collinear. In preferredconstructions, the engagement means engages and forms a releasable unionwith the laterally extending top edge of the filter plate, preferably ata location substantially vertically above the center of gravity of theplate.

The filter press may also be fitted with a means of introducingpressured air into a plurality of channels or ducts defined within thestructure of the filter plate. The air introduction means is adapted forintroducing the air to a port positioned on the top of the platepreferably at a location vertically above the plate's center of gravity.The pressurized air is utilized to urge the filter cloths outward awayfrom the surface of the plate frame, thereby breaking up the cakeconcentrations adhering to the cloths.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a filter press of the instant inventionillustrating the displacement of a carriage, in association with afilter plate, along a guide track;

FIG. 2 is a top view of a filter press showing the filter plate closingaction of a hydraulic ram-fitted follower against an array of filterplates;

FIG. 3 is a side view of a carriage of the instant invention;

FIG. 4 is an elevated perspective view of the carriage shown in FIG. 3illustrating a first pawl in a first or raised orientation;

FIG. 5 is an elevated perspective view of the carriage shown in FIG. 3illustrating a first pawl in a second or lowered orientation;

FIG. 6 is a side view of a carriage of the instant invention exposingthe interior of that carriage in a cut-away view;

FIG. 7 is a top view of the carriage shown in FIG. 6;

FIG. 8 is an end view of the carriage shown in FIG. 6;

FIG. 9 is an elevated perspective view of the pressurized, rodlesscylinder drive means of the instant invention;

FIG. 10 is an end view of the pressure cylinder shown in FIG. 9;

FIG. 11 is an elevated perspective view of a second rodless cylinderdrive means of the invention;

FIG. 12 is an end view of the rodless cylinder shown in FIG. 11;

FIG. 13 is an elevated perspective view of a third rodless cylinderdrive means of the instant invention;

FIG. 14 is an end view of the rodless cylinder shown in FIG. 13;

FIG. 15 is a partial perspective view of a synchronizing means of theinvention shown fitted with a stabilizing means;

FIG. 16 is a partial side view of an engagement means of a stabilizingmeans;

FIG. 17 is a partial elevational view of the filter press illustrating asynchronizing means in association with a stabilizing means;

FIG. 18 is a partial perspective view of a synchronizing means of theinvention fitted with an air introduction means;

FIG. 19 is a partial elevational view of a filter press illustrating anair introduction means;

FIG. 20 is a side view of a filter plate; and

FIG. 21 is a schematic view of a flow diagram of the invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

As shown in FIG. 1, a filter press of the type to which the instantinvention may be fitted, includes a plurality of filter plates 15arranged along a generally elongate frame 16. The filter plates 15 aremade slidable along the length of the frame 16 in a directionsubstantially parallel to the longitudinal axis 20 of that frame 16. Theplates 15 are held in position by a fixed head plate or support 22 whichextends upright and forms a barrier precluding further displacement ofthe plates 15 along the direction indicated by arrow 24.

A moveable follower 26 is positioned substantially opposite the plate 22on the frame 16. The follower 26, as shown in FIG. 2, is made moveablealong the tracks 28 of the frame 16 by the action of a hydraulic ram 30.As shown, the ram 30 is extended in the direction shown by arrow 32,thereby impacting against the moveable follower 26. Follower 26 impactsagainst the assemblage of filter plates 15 eventually pushing orcompressing those plates against the head plate 22. As shown in FIG. 2,the compression of the various plates 15 into an assembly forms acompacted filter press array which is held together in a sealedrelationship by the pushing action of ram 30. This sealed arrayfacilitates an introduction of solids ladened liquids into that filterplate assemblage for purposes of filtering the solids from the liquids.

Fitted along the side of the frame 16 is a guide track 34 which is agenerally elongate member having a longitudinal axis 36. Axis 36 ispositioned substantially parallel to axis 20 of frame 16.

Various configurations of guide track 34 are within contemplation. Asshown in FIG. 10, the guide track 34 may be a pair of elongate "V" crosssectioned channels 34A which extend along opposite faces of a rigidstructural member 35A. An alternate construction is shown in FIGS. 4 and5 wherein the guide track 34 includes an elongate recess well 34Cpositioned between two elongate extensions 34D. Extensions 34D areoriented spacedly from one another and parallel to the longitudinal axis36.

Mounted on the track 34 in a sliding relationship thereto is a carriage38. As shown in FIGS. 3 through 8, the carriage 38 includes a bracketattachment means 40 which slidably connects the carriage 38 to the guidetrack 34. The bracket member 40A construction, shown in FIGS. 5 through8, is an elongate block-like structure having a generally quadrilateralcross section. The bracket 40A includes an elongate lip 41, whichextends into recess well 34C and provides a means to stabilize thecarriage on the guide track 34. The width of lip 41 is sized to beslightly smaller than the distance separating the extensions 34D.

In an alternate bracket 40B construction, as shown in FIGS. 9 and 10,the bracket may include an elongate "U"-shaped structure 43 surmountedby an elongate, generally block-like, platform 45.

As shown in FIGS. 4 through 8, the carriage 38 is a generally elongatebody which extends along a longitudinal axis 44. The carriage structure38 includes a flat planar base 47 surmounted with two upright panels 48positioned parallelly and spacedly apart. Panels 48 and base 47 aresubstantially planar in configuration. The carriage structure 38includes a pair of generally "U"-shaped channels 46 which are positionedon the free ends 49 of the upright panels 48. A pair of upright supports50 are positioned proximate the upstanding panels 48 and extend almostto the inverted "U"-shaped channels 46.

Positioned pivotedly within the structure of carriage 38 are a pair ofpawls: a first pawl, generally 52, and a second pawl, generally 54. Bothpawl 52 and pawl 54 are held within the structure of carriage 38 by arespective pivot pin 56. Each pin 56 extends from one panel 48 through arespective pawl and is mounted within the opposing panel 48 to form agenerally horizontally positioned rotational axis for the pawl. Each pin56 facilitates the reciprocation of its pawl in a generally verticalplane. As shown, this axis may be formed by a bolt 58 which is insertedthrough apertures 60 defined within the panels 48 of carriage 38. Thebolt 58 extends through the panel 48 and subsequently through thestructure of the support 50. Thereafter, the bolt enters a generallycylindrical channel 62 defined within the structure of the pawl. Thebolt 58 exits the pawl, passes through an aperture within the opposingsupports 50, as well as the opposing panel 48.

The end of the bolt 58 may be fitted with a plurality of male threads64. The threads 64 are dimensioned to mechanically cooperate with a nut66 whereby bolt 58 forms a pivot for the respective pawl. The bolt isheld within the structure of member 42 by nut 66.

As shown in FIGS. 3 and 6, a coil spring 55 has one end which is mountedupon the base 47 of the carriage 38. The spring 55 extends uprighttherefrom to be received within the recess well 57 of the pawl 52.Spring 55 is shown in a compressed condition in FIG. 3. In itscompressed position (shown in FIG. 6) the spring 55 urges the pawl 52into a first condition, i.e., a raised orientation. The terminology"first condition," as used herein, should be understood to indicate thatthe pawl 52 has an abutment surface or face 78 which extends above theuppermost surface level 80 of the carriage 38 sufficiently to engage andretain a filter plate 15. The pawl 52 is also positionable in a secondcondition or lowered orientation. In this second condition, the abutmentsurface 78 of the pawl 52 is positioned sufficiently low that it doesnot engage and retain a filter plate 15. Comparing FIG. 3 with FIG. 6,the pawl 52 in FIG. 6 is in a first condition or raised orientation,whereas the pawl in FIG. 3 is in a second condition or a loweredorientation.

Comparing FIGS. 3-8, pawl 52 is a generally elongate body having agenerally quadrilateral cross section. The pawl 52 has a proximal end61, which is proximate the pivot mounting of the pawl. The distal end 63includes a generally planar surface abutment face 78. The abutment face78 is oriented generally transverse to the longitudinal axis 79 of thepawl 52. The pawl 52 includes a smooth planar sliding surface 69. Thissurface 69 is held in a generally angulated orientation with respect tothe longitudinal axis 79 when the pawl is in its first condition. Thesurface 69 is brought into contact with the handles 81 of the filterplates 15 as the pawl is displaced toward the closed side 450 of thefilter press, as indicated by arrow 472. Upon the surface 69 contactingone of those handles 81A, the handle forces the end 63 of the pawl 52downward, permitting the carriage to continue onward. Once the end 63clears the handle 81A, the end 63 is forced upward by spring 55 intothat space 82 between the adjacent handles 81. In this positioning, theabutment face 78 is in abutment against the side 83 of handle 81A.

Positioned opposite pawl 52 and spacedly positioned from pawl 52 is asecond pawl 54, as shown in FIGS. 3, 6 and 7. Pawl 52 and pawl 54 arepositioned apart from one another so as to define an openingtherebetween, denoted generally 85. Pawl 54 is a generally elongatemember composed of two definable sections 54A and 54B. Each of thesesections is itself an elongate member having a generally quadrilateralcross section. The sections 54A and 54B are conjoined in an angulatedorientation, as shown. The proximal end 87 of pawl 54 is proximate thepivot mounting 90 of that pawl. The structure of the pivot mounting 90is substantially identical to the pivot previously described for pawl52. The end 91 of the pawl 54 defines a planar surface which functionsas an abutment face 92 for pawl 54. The plane of abutment face 92 isoriented substantially perpendicular to a longitudinal axis 93 of thepawl section 54B. Abutment face 92 is positioned opposite abutment face78 of pawl 52 across opening 85.

As shown by comparing FIGS. 6 and 7, the faces 91 and 78 of pawls 54 and52 define a generally quadrilaterally cross sectioned space, i.e.,opening 85. This space 85 is dimensioned to receive a handle 81 of afilter plate 15 and releasably retain that handle 81. This retentionpermits the displacement of that filter plate by the abutment of thepawls 52 and 54 against that plate 15.

The pawls 54 and 52 are mounted about the pivots 90 and 71 respectivelyto rotate in a generally vertical plane i.e., the axis defined by pivots90 and 71 are each horizontal.

The conjunction of section 54A with section 54B is made at an angle,i.e., section 54A extends in an angulated manner from the section 54B todefine a generally obtuse angle therebetween denoted generally 96. Thepawl 54 includes a recess well 100 positioned on its lower face 102.Well 100 is dimensioned to receive a coil spring 104. The coil spring104 is positioned on the base 47 of the carriage 35 and extends upright,i.e., vertically and is received within the recessed well 100.

As shown in FIGS. 3 and 6, the coil spring 104 is constructed to exert aresilient force against the pawl 54 and thereby retain that pawl in anupright first condition or raised orientation. It should be recognizedthat upon a sufficient force application along a direction indicated byarrow 108, the pawl 54 is depressed downward about its pivot axis. Undersufficient force application, the pawl's distal end 91 may be receivedwithin the interior of the carriage 38. In a similar manner to thatpreviously described for pawl 52, pawl 54 may be positioned between oneof two conditions. In a first condition or raised orientation, the pawlmember 54 extends beyond the uppermost surface 80 of carriage 38. In asecond orientation, the pawl 54 is positioned beneath that plane 80,i.e., within the very structure of the carriage 38.

Positioned within the channel 46 of the carriage member 38 is a pair ofshaft-like cylindrical members 116. As shown in FIGS. 4, 5 and 8, themembers 116 are positioned atop supports 50 and slide along the topsurface of those supports. As shown in FIGS. 7 and 8, the cylindricalmembers 116 each include a longitudinal axis 118. Axes 118 are orientedparallel to the longitudinal axes 20 and 44 of the filter press andcarriage, respectively. Shafts 116 are positioned parallel to oneanother and spacedly apart. Positioned proximate the ends 117 of eachshaft member 116 is a cross-member 120 which extends from one shaftmember 116 to the oppositely positioned shaft member 116. Eachcross-member 120 may also be a cylindrical shaft. As shown, the ends 132of shaft members 116 extend outwardly from the ends 122 of the carriagemember 42. The cross-member 120, which is indicated generally by thenotation 130, is positioned in a predetermined relationship with thepawl 52. This relationship is such that upon the ends 132 of the shaftmembers 116 being inserted into the channels 46 of the carriage member42 sufficiently so that the ends 132 are substantially flush with theend 122 of the carriage member 38, the cross-member 130 is positionedsufficiently above the pawl 52, as to hold that pawl in its lowerorientation, as shown in FIG. 5. In this orientation, the opposing ends134 of each shaft 116 are extended proportionality outward from the end136 of the carriage member 42.

An opposing displacement of the shaft members 116, in the directionindicated generally by arrow 140, results in the disengagement of thatcross-member 130 thereby permitting the return of the pawl 52 to itsraised orientation, as shown in FIG. 4. It will be recognized thereforethat the displacement of the shaft member 116 directed toward either endof the carriage end affects a displacement of the cross-members 130 and120 into either an orientation wherein pawl 52 is depressed oralternately into an orientation wherein the pawl 52 is urged into itsuppermost orientation.

As shown in FIGS. 9 and 10, a drive means of the invention may include afluid pressure cylinder 150 defined by a generally cylindrical tubularsidewall 152. Sidewall 152 defines a hollow interior cavity or channel154. Sidewall 152 is elongate and extends along a longitudinal axis 160.The sidewall 152 defines a slot-like aperture 156 which extendssubstantially the entire length of the sidewall 152. The slot 156includes as its perimeters the edges 158 of the tubular sidewall 152.

The channel 154 shown in FIG. 10 is substantially circular in crosssection and is hence cylindrical in configuration. Fitted within thechannel 154 is a cylindrically configured piston 162. Piston 162 isdimensioned and configured to be reciprocally slidable within thechannel 154. Positioned on each end of the cylinder 162 is a plate 164respectively designated 164A and 164B. The plate 164 in conjunction withthe portion of the interior sidewall 166 which defines channel 154 aswell as the end plates 170 define a pair of pressure chambers 172, morespecifically, chambers 172A and 172B.

As shown in FIG. 9, each pressure chamber 172 is substantially sealedwith the exception for the slot 156 defined by the side wall 152. Asealing strip 174 is provided to be inserted within slot 156 and to forma seal of that slot whereby each pressure chamber 172 is thereby sealedair tight, permitting a pressurization of that chamber. Air supplyconduits 180 and 181 each access a respective pressure chamber 172 andprovide a means whereby pressurized air may either be introduced intothe chamber or alternately withdrawn from the chamber.

The piston 162 is fitted with a means of successively positioning thestrip 174 within the slot 156 or alternately removing that strip tofacilitate the passage through the slot 156 of a neck-like region of acarriage/piston support mounting 182. The mounting 182 connects thecylindrical piston 162 to the carriage 38. Any displacement of piston162 results in a corresponding and equal displacement of the carriage38. The piston fitted tubular member, commonly denominated a "rodlesscylinder," is presently available commercially under the tradedesignation "Lintra" and is marketed by Martonair, Inc. of Agawam, Mass.

A more thorough discussion of the construction of a type of rodlesscylinder employable in the instant invention is that made in LiebermanU.S. Pat. No. 4,545,290 The specification of that patent is incorporatedherein by reference.

The top of the rodless cylinder may form a guide track 34 upon which thecarriage 38 may slide.

As shown to advantage in FIG. 10, the carriage mounting may include aplatform 190 having a generally inverted "U"-shaped configurationwherein the arms 194 of that "U"-shaped configuration are fitted withinwardly directed extensions 196. These extensions are configured to bereceived within "V"-shaped channels 198 configured within the side ofthe rodless cylinder 150.

The neck 182 of the platform 190 extends downward through slot 156 andis thereafter fitted to the piston 162 through means of the yoke 200.The sealing slide strip 174 is fixedly mounted to the ends 170 of thecylinder and laid within slot 156. The strip is positioned through theopening 202 defined within the yoke 200. As the piston reciprocateswithin the channel 154 the strip is either positioned within the slot156 or removed therefrom by the action of the yoke. This permits thepassage through slot 156 of the neck 182.

Alternate constructions of a rodless cylinder for use in the instantinvention are disclosed in FIGS. 11 through 14. In FIGS. 11 and 12, anelongate tubular member 213 defines a hollow cylindrical cavity 211which in turn defines two pressure chambers 215A and 215B. A piston 217is slidably positioned within the cavity and serves to separate onepressure chamber from the other. The tubular member 213 does not includea slot 156. Each pressure chamber is fitted with an inlet port 216 foreither injecting or venting compressed air into the chamber. An elongateflexible band or cord 218 is affixed to the piston 217. A proximal end220 of the cord is affixed to one end of the piston and a distal end 221of the cord is affixed to the opposing end of the piston. The cordextends from the piston outward through a respective pressure chamberand thereafter sealedly through an end wall 223 of the tubular member toform in association with the piston 217 an endless member. The carriage38 is fixedly mounted to the cord such that any displacement of thepiston 217 effects a corresponding displacement of the carriage 38.

In FIGS. 13 and 14, the rodless cylinder, shown in FIGS. 11 and 12, ismodified to accommodate a third means of associating the carriage 38with the piston 217. In this construction, the connective function ofthe band 218 is replaced by the use of a magnetic union of the carriage38 with the piston 217. There are no inlets into the pressure chambers215 except for air inlet ports 216. The piston 217 is fabricated from amaterial having magnetic-type characteristics, e.g., an iron compound.Fitted about the exterior sidewall of the tubular member 213 is aringlike collar 231. This collar includes an inner aperture which isdimensioned to slidably receive the tubular member 213, i.e., the collaris adapted to slide along the length of the tubular member 213. Thecollar 231 is likewise fabricated from a material having magneticcharacteristics.

As pressurized air is introduced into pressure chambers 215 and thepiston is displaced within the tubular member 213, the collar islikewise displaced due to a magnetic force induced union of the collar231 with the piston 217. As a result, the carriage 38 is reciprocatedalong the length of the tubular member 213 responsive to the pressurizedair induced displacements of the piston 217.

Other rodless cylinders which may be used in the instant invention arethose sold commercially under the trade designations "Trans-air System"manufactured by Mosier Industries, Inc. of Brookville, Ohio; "Series2000" manufactured by Orija Corp. of Elmhurst, Ill.; and "BandCylinders" manufactured by Tolomatic of Minneapolis, Minn.

As shown in FIG. 20, the carriage 38 of this instant invention may, in apreferred embodiment, be fitted with a means of supplying pressurizedair to an interior conduit system 206 positioned within a filter plate15A.

As shown in FIGS. 15-17, a pair of carriages 38 spacedly mounted apartfrom one another on opposing sides of a filter press may be physicallyassociated with one another by means of a synchronizing means 208. Inthis embodiment, the carriage 38 is formed as an elongate hollow tubularmember having a generally quadrilateral cross-section. The carriage 38defines a square cross-sectioned interior channel 209 having opposingopen ends. The rodless cylinder 150 is received within the channel 209.Basically, the carriage forms a sleeve which circumscribes the rodlesscylinder 150. The carriage 38 is slidable along the length of thecylinder. The size of the channel 209 is dimensioned sufficientlyproximate the exterior dimensions of the cylinder as to preclude arotation of the carriage 38 around the cylinder 150 about thelongitudinal axis of the cylinder.

Mounted on the outside upright wall 210 of the carriage 38 is an"L"-shaped mounting bracket 212. A generally inverted "U"-shaped rigidrod 214 is mounted at each of its ends to a respective bracket 212whereby the rod 214 extends between the two opposing carriages 38A and38B (see FIG. 17).

The rod 214 is sufficiently rigid that the motion or displacement of onecarriage 38 is transmitted to the other carriage through the rod. Itfollows that as the two carriages 38 proceed along the length of theirrespective cylinders, their respective displacements are synchronized bythe operation of the rod 214. Should one carriage 38 encounter anobstacle, e.g., a sludge deposit which either slows or stops thecarriage's forward or backward displacement, the other carriage is alsoeither slowed or stopped. Recognizably, the force being imposed on thecarriage which has not encountered the obstacle, by its respectivecylinder, will be in part transferred to the obstacle encounteringcarriage through intermediation of the rod.

The function of rod 214 becomes important when one realizes that afilter press, which utilizes a fluid cylinder as its drive means, relieson a fluid pressure to drive the carriages along their appointed routes.The amount of force being applied by the cylinders is a function of thedrag resistance being encountered by the carriages. As a result, when acarriage encounters an obstacle, the cylinder must build up a sufficientfluid pressure to apply a force of a magnitude to overcome that force.The delay associated with building up that fluid pressure may lead tothe opposing carriage advancing beyond the encumbered carriage andthereby misaligning the filter plate being driven jointly by the twocarriages. Mechanical drive systems such as those utilizing sprocketdriven chains conventionally apply a constant drive force uniformly toboth of the opposing carriages. The force applied is typically of amagnitude sufficient to overcome any resistance encountered by atraveling carriage. Furthermore, the two chain drives typically areconnected to a common power source, e.g. a motor. Therefore, in theevent that one of the carriages encounters an obstacle which offerssufficient resistance that the speed of the carriage is effected, thedecrease in carriage and hence chain speed is communicated directly tothe driven motor. The drive motor then simultaneously effects acorresponding decrease in carriage speed to the non-obstacleencountering carriage. Thus no misalignment of the filter plates occurs.

In contrast, the instant invention in utilizing a pair of drive means,i.e. pressure fluid cylinders, introduces the possibility ofmisalignment occurring in that a single drive source cannot be reliedupon to synchronize the displacement of the two carriages.

In the embodiment shown in FIG. 15, the carriages 38 are shown mountedproximate the upper region of the filter plates 15 being moved. As shownto advantage, in FIG. 17, an inverted "L"-shaped mounting bracket 219 ismounted on each of the upright sides 218 of the plate 15. Each of thebrackets 219 ride atop an elongate, longitudinally extending guide rail218. Each bracket 219 is mounted with a handle 220 which is fabricatedof a material having a low coefficient of friction such that the slidingdisplacement of the bracket along the rail 218 is not unduly hindered.The handle 220 includes an extending finger 221 dimensioned to bereceived within the space defined by the opposing pawls 52 and 54.Recognizably, the handle 220 could be mounted on the upright sides ofthe filter plate 15. In this latter construction, the rod 214 is simplyextended in length so as to extend the alternate carriage location. Thisalternative carriage location is shown in FIG. 19.

The rod 214 may also be fitted with a means of stabilizing thetransported filter plate 15, especially against angular rotation about alateral axis 223. Recognizably, due to the need for spacing between theopposing pawls 52 and 54 of each carriage, the handles 220 are notsecurely grasped by those pawls. As a result, the plate 15 may tend torock as it is transported along the press by the displacing carriage 38.As shown to advantage in FIGS. 15-17, a vertically extending bar 224 ismounted on rod 214 proximately midway along the laterally extendingportion of that rod 214. The bar 224 extends downwardly from the rod 214to a location proximate the top of a filter plate 15 being transported.Mounted on the free end 226 of bar 224 is a carriage 230. As shown inFIGS. 15 and 26, carriage 230 is structurally identical to the carriageassembly 42 shown in FIG. 2. Two pawls 232 and 234 are pivotedly mountedin the carriage 230 by means of respective laterally extending pivotbolts 236 and 238. Each of the pawls is formed on its downward facingsurface with an exterior configuration adapted to function similarly tothe corresponding surfaces 462, 464 and 456 of pawls 52 and 54 apreviously described.

The filter plate 15 is fitted on its top edge with a handle 239 whichextends vertically upward. The handle 239 is dimensioned to be receivedin the space defined between the opposing pawls 232 and 234. The handles239 of adjacently positioned filter plates 15 are configured to providethe same camming action as the pawls 232 and 234 as previously describedfor the carriages 42. In preferred constructions, the handle 239 ismounted midway between the opposing upright sidewalls 240 of the filterplate 15. Preferably, the handle 239 is mounted directly above thecenter of gravity of the filter plate 15. Understandably, the instantlydescribed stabilizing means may be positioned to engage the filter plateat locations other than on the top edge of the filter plateapproximately midway between the upstanding sides of the plate.

Recognizably, the invention may include any arrangement wherein thecarriage/synchronization bar structure is mechanically connected to thefilter plate at three separate and distinct locations which are notcollinear in orientation. For example, two connection points may bealong a single upright side of the filter plate while the third is alongan opposing upright side. In these alternative constructions, thesupport bar of the stabilizing means extends from the rigid bar 214 to apoint proximate the filter plate. The carriage 38 and filter platehandle are structurally identical to those previously described.

The invention also includes a means of introducing pressurized air to asystem of conduits defined within the frame of the filter plate itself.A filter plate of a type amenable to pressurized air introduction isshown in FIG. 18. Whereas applicant's previous disclosure illustrated anair introduction means wherein the air was input into the plate by meansof a carriage carried nozzle which interacted with the laterallyextending handles of the plates, the present invention contemplates theintroduction of air through a bayonet-type nozzle assembly 242 which ismounted on the rod 216. Nozzle assembly 242 is of a conventionalpressurized bayonet-type air injection nozzle which, upon theapplication thereto of a quantity of pressurized, air, an air conveyingconduit extends outwardly into a sealed engagement with an inlet portmounted on the plate 15. As shown in FIGS. 18 and 19, the nozzle 242 ismounted to be positioned vertically above the center of gravity 243 ofplate 15 and along the vertical axis of the plate 15. Nozzle 243 issupplied by pressurized air by a flexible conduit 244 which is connectedto a source of pressurized air (not shown). The conduit 244 is supportedby a longitudinally extending rod 245 which may be of a telescopicconstruction whereby the rod 245 may extend and retract with thenozzle's displacement along the press. As shown in FIG. 1, the rod mayextend from the closed region 450 of the press. Alternatively, the rod245 may extend from the open section 452 of the press. The rod 245 isgenerally supported by a frame or other support structure of the press.In one embodiment, the rod 245 may be replaced by a flexible cable whichsimilarly supports the flexible air hose 244.

The flow logic of the plate shifter control system is shownschematically in FIG. 21. For purposes of clarity, the followingdescription will utilize pressurized air as the activation medium. Itshould be understood that any pressurized fluid may be used, i.e., thesystem may be either pneumatically or hydraulically actuated. Asillustrated, pressurized air is injected into a conduit 250 by means ofport 252. The air passes through a filter 254 and a pressure regulatingvalve 256. A gauge 258 is connected to valve 256 and functions tomonitor the pressure of the air flow in conduit 250. The air then passesthrough a lubricator 260.

Conduit 250 branches into two conduits 262 and 264 at Tee connectionjoint 266. Conduit 262 is fitted with a switch 268, which is preferablymanually operated. The two way switch 268 functions to switch the systemfrom a manually operated system to an automated system and vice versa.

In the manual mode, conduit 262 is interconnected to conduit 270 byswitch 268. Air flows through conduit 270 eventually reaching a Teeconnection 274. At Tee 274, conduit 270 branches into two conduits 276and 278. Conduit 276 leads to a pendant two-way valve 280. Valve 280 isa manually operated, spring return valve having two orientations. Thetwo orientations are depicted in the square box-like outlines 282 and285. The valve orientation, shown in box 282 and illustrated proximatethe manual button 284, is the orientation effected by depressing button284. The orientation shown in box 285 is that obtained by the springreturn, i.e., the orientation in box 285 depicts the equilibriumposition of the valve 280.

As the button 284 is depressed, valve orientation 282 permits air flowfrom conduit 276 through valve 280 and into connected conduit 286. Whenthe valve 280 is in its equilibrium position, flow of air from conduit276 through valve 280 is precluded.

Air entering conduit 286 is directed by Tee connection 288 into conduits290 and 292. The air flowing in conduit 292 is directed by spindle valve294 into conduit 296. Spindle valve 298, which is fitted to conduit 296,directs the air from conduit 296 into conduit 300. The air in conduit300 is directed to a pressure operated two position valve 302. Thepressure of the air in conduit 300 shifts valve 302 into an openorientation depicted in box outline 304. When the valve 302 is notpressurized by air in conduit 300, a spring returns the valve 302 to itsequilibrium position as depicted in box outline 306. In the valveorientation depicted by outline 304, conduit 310 is connected to aconduit 312 and a conduit 314 thereby permitting flow between those twoconduits.

The pressurized air within conduit 300 does not pass through valve 302,but instead serves to retain the valve 302 in its actuated orientation,i.e., the orientation indicated by box outline 304. When valve 280 isreturned to its equilibrium position, i.e., the orientation indicated at285, the air in conduit 300 is vented to the atmosphere through the flowpath defined by conduit 296, conduit 292, conduit 286 and valve 280.

Valve 302, in the orientation illustrated by box 306, precludes thepassage of pressurized air from conduit 312 to conduit 314.

Conduit 312, in conjunction with conduits 264, 320 and 314, defines anair drive line. These conduits channel that portion of the pressurizedair which moves the drive piston 162.

Positioned between conduits 264 and 320 is a two position manual valve322. Valve 322 is pressure returned to the equilibrium orientation,depicted by box outline 324, by air pressure channeled through conduit329. In the orientation illustrated in box outline 324, air flow fromconduit 320 is vented to the atmosphere.

In the orientation depicted by box outline 326, pressurized air fromconduit 264 is directed into conduits 320 and 312. As air flows throughthe four-way connection joint 330, which connects conduit 320 withconduit 312, air likewise flows into conduit 332.

Conduit 332 is fitted with a pneumatically actuated indicator 334.Indicator 334 is adapted to provide a visual indication of the presenceof air in the system. Pressurized air, which is received from joint 330and which flows into conduit 336, is precluded from further flow throughthat conduit by check valve 340.

With valve 322 in the orientation shown by box outline 326, and valve302 in orientation illustrated in box outline 304, pressurized air maybe received from port 252 and channeled to conduit 314. The air fromconduit 314 is directed to a two-way pressure activated valve 342.

As shown, valve 342 is positioned in a first orientation shown in box344 by air pressure within conduit 346. That pressure is engendered whenthe valve 280 has been manually activated, i.e., to an orientation shownby box outline 284, and pressurized air flows into conduit 290 and isdirected into conduit 246 by spindle valve 350. In the orientation shownin box 344, valve 342 directs air from conduit 314 to conduit 352.Pressurized air flows through conduit 352, past Tee connection joint354, and Tee connection joint 356 to Tee connection joint 358. Teeconnection joint 358 connects conduit 352 to conduit 355. Thepressurized air flowing in conduit 355 is directed past check valve 360into a sealed pressure chamber 172B. The increase of air pressure withinchamber 172B operates to displace piston 162 due to the force acting onpiston head 164B. Piston 162 is displaced in the direction indicated byarrow 364.

Positioned between the two connection units 366, which are placed withinconduit 355, is a needle valve/pressure regulator 368. Valve 368 isadapted to control the outward flow of air from the chamber 172B to theconduit 352.

In those embodiments wherein two pressure cylinders are used, i.e., oneon each side of the filter plate array, a needle valve 368 is positionedwithin each feed conduit 355 of a respective pressure chamber 172Bthereby permitting the synchronization of those pressure cylinders bycontrolling the discharge of air from the pressure chambers 172B.

All air discharged from the chamber 172B is routed through valve 368since check valve 369 precludes a passage of discharged air throughconduit 355.

Tee connection 356 directs air from conduit 352 to a pressure regulatingvalve 360. Valve 370 is adjusted to permit a passage of air therethroughupon air pressure in conduit 372 reaching a selected level.

Operationally, the disparity in pressure between pressure chambers 154Aand 154B causes the piston 162 to displace carriage 38. Since thatcarriage 38 abuts against a filter plate 15A, the plate is alsodisplaced. Once filter plate 15A is precluded from further movement inthe direction of the moving carriage, the motion of the carriage andpiston is precluded. Since the piston is precluded from further forwardmovement the air pressure in conduit 352 builds. When that pressurereaches the level necessary to activate valve 370, the air from conduit352 is directed from conduit 352, into conduit 372, through valve 370,and into conduit 376. Check valve 378 channels the air from conduit 376into conduit 380. The pressure of the air in conduit 380, soon exceedsthe pressure of the air in conduit 346 and thereby displaces valve 342into the orientation identified by the outline 348. The valveorientation as indicated by outline 348 directs the flow of pressurizedair from conduit 314 into conduit 382 while it simultaneously vents theair contained within the conduit 352.

Pressurized air in conduit 382 is directed to Tee connection joint 384.Flow into conduit 386, which conduit extends from that joint 384, isprecluded by check valve 388. Resultingly, the pressure air is channeledinto conduit 389.

Conduit 389 directs the air flow to Tee connection joint 392. Flow intoconduit 394, which extends from joint 392, is precluded by pressureregulating valve 396, until the pressure in conduit 394 exceeds aselected value. When the air flow in conduit 389 is below the selectedpressure valve, the air flow is directed through conduit 400, past checkvalve 402 into the pressure chamber 172A. As the pressure increaseswithin chamber 172A, the piston 162 is displaced in the directionindicated by arrow 404.

As the carriage 42 abuts against a filter plate which is precluded fromfurther displacement in the direction indicated by arrow 404, thepiston's displacement is likewise precluded. The continued addition ofpressurized air into the system, specifically in pressure chamber 172A,results in the pressure within the conduit 394 increasing to theselected pressure value of valve 396. Resultingly, the valve 396 isopened, permitting air flow from conduit 394 into conduit 410. The airin conduit 410 is directed by spindle valve 412 into conduit 346. As theair pressure in conduit 346 increases it eventually overcomes thepressure in conduit 380 and thereby valve 342 is shifted by that airpressure into the orientation depicted by box outline 344. This valveshift directs air flow into channel 352.

The pressurized air within chamber 172A may be discharged from thatchamber by passage through needle regulatory valve 420. Discharge flowthrough conduit 400 is precluded by check valve 402. The discharged airis directed through conduit 400, conduit 389, and conduit 382 eventuallybeing vented to atmosphere through valve 342.

A counterpart valve 422 to valve 280 is connected to conduit 278. Valve422 is a two-position, manually operated valve positionable between twoorientations identified by box outlines 424 and 426. The valve 422, inits spring biased, equilibrium position 424, precludes air flow throughthe valve. The orientation 426 which is obtained by manually depressingbutton 428 defines a flow channel from conduit 278 into conduit 430. Airflow within conduit 430 is directed into conduit 296 by spindle valve294. Valve 422 also channels air flow along conduit 432 to spindle valve378 and thereafter into conduit 380. This air flow in conduit 380effects a shift in valve 342 to the orientation designated by boxoutline 348.

Resultingly, air received into conduit 324 by the activation of valve302 and 324 is directed through valve 342 into conduit 382. From conduit382 it follows the flow path as heretofore described.

In its manual operation mode, the system permits a user to alternate thedisplacement of piston 162 at will by depressing buttons 284 and 428.

The automated system is engaged by positioning switch 268 to directpressurized air flow into conduit 441. The air flows into conduit 300from conduit 441 after being directed by spindle valve 298. The air flowthereby shifts valve 382 into the orientation denoted by box outline304. This orientation permits an air flow from conduit 250, throughconduits 264, 320 and 312 into conduit 314, given the positioning ofvalve 322 in its orientation denoted by box outline 304.

The air flow enters valve 342 and is channeled thereby into eitherconduit 382 or conduit 352 depending on the particular orientation ofthe valve 342 prior to the initiation of the system's operation. Thefollowing description will assume that flow was into conduit 382.

As air flows through conduit 382, it effects the displacement of thepistons 162 in the direction indicated by arrow 404. Upon the pistons'forward progress being arrested by the carriages 42 abutting against afilter plate 15, the accompanying increase of air pressure within thepressure chamber 172A exceeds the preselected level of valve 396 causingthe bypassing of that valve. Thereafter, the pressurized air flow isdirected against valve 342 to shift that valve to the orientationidentified by box outline 344. The air flow from conduit 314 isthereafter directed to conduit 352. The air flow forces a displacementof pistons 162 in the direction indicated by arrow 364. Upon thecarriages 42 abutting against an oppositely positioned filter plate 15the pistons' progress is again arrested. As pressure continues to buildin pressure chamber 172B, the pressure level of valve 370 is exceededcausing the bypassing of that valve. Thereafter, air flow is directedpast valve 370 into conduit 376. Spindle valve 378 directs the flow intoconduit 380. The air in conduit 380 acts on the pneumaticallymanipulated valve 342 to shift it into the orientation denoted by boxoutline 348.

This shifting from the valve 342 between the orientations identified bybox outlines 344 and 348 continues as the carriage is driven between theopen array 452 of filter plates and the closed array 450 of filterplates.

Upon the last filter plate from the closed array side 450 of the filterpress being transferred to the open side 452 of the frame, the last tripof the carriage 42 along the guide track 39 toward the closed side 450results in the carriage impacting against the stop 454. Morespecifically, the ends 132 of the side members 116 impact against thestop 454.

The slide members 116 are slidably mounted in the channels 46 ofcarriage 42. Resultingly, the ends 132 are driven toward the end 122A ofeach respective carriage 42, until the ends 132 are flush with thesurface 122A. This results in the cross-members 130 being pushed alongthe surfaces 453 of each pawl 52. The cross-member 130 forces each pawl52 into its lower orientation as shown in FIGS. 3 and 5. This shiftingof each pawl 52 into its lower orientation results in the compression ofspring 74.

Since the forward progress of carriages 42 is arrested due to theirabutment against stops 454, the flow circuitry reverses the direction ofthe pistons 162 and carriages upon sufficient pressure being generatedwithin the conduit proximate the pressure regulated valve, i.e., valve370 or valve 396.

As the carriages 42 are driven toward the open side 452, the edges 460of the filter plates 15 impact against surfaces 462 and 464 of sections94 and 92 of each pawl 54. Due to the angled orientation of surface 462and the resilient spring support of each pawl 54, the filter plate edgesslide along the surface 462 and thereafter along surface 464. Each pawl54 is depressed by the filter plate edges against the action of itsrespective spring 107. Each pawl 54 does not catch against the filterplates 15 on the open side 452, nor do the filter plates substantiallyarrest the progress of the respective carriage 42, as the carriage 42moves in the direction indicated by arrow 364 until it impacts against afilter plate 15 positioned on the closed side 450 of the frame.

Each abutment face or surface 78 is depressed below the upper surface 80of the carriage 42 by the cross-member 130 sufficiently that it alsodoes not catch the edges of the filter plates as the carriage passesbelow those edges 460.

Upon each carriage 42 reaching the end of its guide track 34, it impactsagainst a stop 470. The impact forces slide members 116 in the directionindicated by arrow 472. The impact forces the slide members into eachcarriage until ends 134 of those slide members are flush with surface122B of each carriage 42. This displacement of the slide members issufficient to remove each cross-member 130 from its depressingengagement against a respective pawl 52. As a result, the pawl 52 ofeach carriage 42, due to the action of a respective spring 104, returnsto the raised orientation shown in FIG. 4.

Positioned proximate each stop 470 is a disengagement button 476 whichis connected to a regulatory valve 478. Upon carriage 42's impactagainst stop 470, the carriage 42 likewise impacts against button 476thereby engaging said button. Valve 478 has two positions. One positionis activated by the depression of button 476. Upon release of thedepressing force, a spring returns the valve to its equilibriumposition. The depressed valve orientation is shown in FIG. 13 in boxoutline 482. The equilibrium orientation is shown in box outline 480. Asshown, the equilibrium orientation precludes air flow through theconduit 484. The orientation shown in box outline 482 permits flow fromconduit 484 into conduit 492.

Conduit 492 includes a flow restrictor 495. Conduit 492 is connected toa pressure sensitive regulator valve 498 similar to those identified as370 and 396. Upon the air pressure in conduit 492 reaching a specifiedlevel, the air flow bypasses valve 498 and enters conduit 500. As theflow in conduit 500 enters Tee connection joint 502, the flow isdirected into conduit 506. As the pressure builds in conduit 506, thepressure actuated valve 332 is shifted to the orientation indicated inbox outline 324. This valve shift interrupts the supply of pressurizeddriving air to the system.

Any air in conduit 504 is directed through check valve 508. Itthereafter is directed through connection joint 330 and conduit 320. Itis thereafter vented to the atmosphere through valve 322.

When the system is reactivated, the carriage is moved away from button476 which then shifts valve 478 to its equilibrium position.

Those skilled in the art will recognize that the embodiments herein anddiscussed are illustrative of the general principles of the invention.The embodiments herein described are not intended to limit the scope ofthe claims which themselves recite what applicant regards as hisinvention.

What is claimed is:
 1. A filter press comprising:a frame, having opposing sides; a press head mounted on said frame; a follower displaceably mounted on said frame spacedly from said press head; a plurality of filter plates mounted on said frame between said press head and said follower, each said filter plate being displaceable along said frame; two rodless cylinders mounted on said frame, said rodless cylinders being mounted on said opposing sides of said frame spacedly apart from another; two connection means, each said connection means being displaceably mounted on a respective said rodless cylinder, for engaging an individual said filter plate and forming a releasable union therewith; and synchronizing means mounted on each of said connection means and extending therebetween, said synchronizing means operating to maintain said two connection means in a substantially fixed spatial relationship with respect to each other as said two connection means are displaced along a length of said frame; wherein an introduction of pressurized fluid into said rodless cylinders effects a displacement of said two connection means along said frame, thereby displacing a said filter plate, engaged by said two connection means, along said frame.
 2. The filter press of claim 1 wherein said synchronizing means is a rigid connection bar mounted to each of said connection means and extending therebetween.
 3. The filter press of claim 1 wherein each said rodless cylinder includes:an elongate tubular member defining a pair of spatially expandable pressure chambers therein, said spatially expandable pressure chambers including means of introducing pressurized fluid into said spatially expandable pressure chambers and venting said fluid from said spatially expandable pressure chambers; and a piston slidably mounted within said elongate tubular member between said spatially expandable pressure chambers, a spatial expansion of one of said spatially expandable pressure chamber causing a spatial displacement of said piston within said elongate tubular member.
 4. The filter press of claim 3 further including two carriages, each said carriage being mounted on said elongate tubular member, each said carriage being associated with a respective said piston wherein a displacement of each said piston effects a corresponding displacement of its respective said carriage, each said carriage being connected to a respective said connection means.
 5. The filter press of claim 4 wherein each of said connection means includes at least one pawl pivotedly mounted on said carriage adapted for engaging and forming a releasable union with a said filter plate.
 6. A filter press comprising:a frame; a press head mounted on said frame; a follower displaceable mounted on said frame spacedly from said press head; a plurality of filter plates mounted on said frame between said press head and said follower, said filter plates being displaceable along said frame; two rodless cylinders mounted on said frame; connection means displacedly mounted on said rodless cylinders for engaging an individual filter plate and forming a releasable union therewith; stabilizing means, mounted on said connection means, for engaging an individual filter plate being displaced by said connection means and retarding, if not precluding, an angular rotation of said individual filter plate about an axis-oriented transverse to a direction of travel of said individual plate; wherein an introduction of pressurized fluid into said rodless cylinders effects a displacement of said connection means along said frame, thereby displacing a filter plate, engaged by said connection means, along said frame.
 7. The filter press of claim 6 wherein said stabilizing means is mechanically associated with said connection means.
 8. The filter press of claim 7 wherein said stabilizing means comprises:a rigid bar, mounted on said connection means; and an engagement means, mounted on said bar, for engaging and forming a releasable union with an individual filter plate.
 9. The filter press of claim 8 wherein said engagement means is adapted to engage and form a union with said filter plate at a location vertically above said filter plate's center of gravity.
 10. The filter press of claim 8 wherein said engagement means is adapted to engage and form a union with said filter plate on a laterally extending side thereof.
 11. The filter press of claim 8 wherein said engagement means includes:a support frame; and at least one pawl pivotedly mounted to said support frame adapted for engaging and forming a releasable union with one of said filter plates.
 12. A filter press comprising:a frame; a press head mounted on said frame; a follower displaceably mounted on said frame spacedly from said press head; a plurality of filter plates mounted on said frame between said press head and said follower, said filter plates being displacedly mounted along said frame; two rodless cylinders mounted on said frame; connection means displacedly mounted on said rodless cylinders for engaging an individual filter plate of said plurality of filter plates and forming a releasable union therewith; and an air introduction means for introducing pressurized air into said individual filter plate, said air introduction means being mounted on said connection means to engage an inlet port mounted on a top of said individual filter plate.
 13. The filter press of claim 12 wherein said air introduction means comprises:a rigid bar mounted on said connection means; and a bayonet-type nozzle mounted on said bar adapted for engaging said inlet port of said individual plate.
 14. The filter press of claim 13 wherein said inlet port is positioned substantially vertically above said individual filter plate's center of gravity.
 15. The filter press of claim 13 wherein said press includes two rodless cylinders are spacedly mounted apart from one another, each rodless cylinder having a respective connection means mounted thereon, said rigid bar being mounted to each of said connection means and extending therebetween. 